The South Australian Greens say they don't see a need for multiple deep-sea ports to be built in the State.

Yesterday, the South Australian Government granted major development status for the multi-billion-dollar Cape Hardy port being planned by Iron Road for its iron ore exports.

The plan also includes transport of the iron ore to the port and a workers accommodation village within Wudinna.

But this is not the only port to have received a status by the government.

Another port, about 10 kilometres south of the Cape Hardy port, is also proposed for the region to export iron ore for Centrex Metals and was given Major Project Status in 2011.

The year after, a deep water development further north at Port Bonython was granted Major Project Status and another iron ore export facility, using a floating harbour, is planned for Lucky Bay, about 100 kilometres south of Port Bonython.

Greens MP Mark Parnell says there needs to be a decision made by the State Government on just one deep-sea port location for the region.

"What doesn't make sense is the Government allowing all of these separate port proposals to be advanced at the same time with no one having a look at what the impact might be if they were all to be successful."

Minister for Natural Resources and Energy Tom Koutsantonis says just because a proposal is given a certain status doesn’t mean it will go ahead.

He says the status does allow the companies to move forward though with looking for investors.

"Being declared a major development gives the ability for these people who are perpetrating these mines to go forward and get more finance and gives them the approvals that they need to proceed and offer their investors a certainty to invest.

"Ultimately, what is going to get these minerals out of the ground and invested is certainty to the market and that is what the Government is offering all the major players on the Eyre Peninsula."

Megan Andrews, from the SA Chamber of Mines and Energy, says it's not certain how many of the deep-sea ports will reach fruition, but for South Australia to have any would be a boon.

"We're talking about a project with huge benefits in terms of job creation and the economic flow-on effects."

She says multiple ports are warranted for future mines.

"Not necessarily more than one on the Eyre Peninsula, but we probably need between two and three [in South Australia]."